A total of 345 subjects with type 2 diabetes will be randomized across approximately 50 centers in this three-month comparative trial. One third will receive combination oral hypoglycemic agent therapy alone, one-third will receive inhaled insulin in addition to combination oral hypoglycemic agent therapy, and one-third will receive inhaled insulin monotherapy. All who successfully complete the three-month trial will be eligible for participation in a long-term, open-label extension of inhaled insulin.